X-ray cone assembly



Oct. 9, 1951 KNAB 2,570,820

X-RAY CONE ASSEMBLY Filed May 29, 1950 IN VEN TOR.

AGENI Patented Oct. 9, 1951 X-RAY CONE ASSEMBLY Max Knab, Brooklyn, N. Y., assignor to Philips Laboratories, Inc., Irvington-on-Hudson, N. Y.

Application May 29, 1950, Serial No. 164,907

The invention relates to an X-ray cone assembly having an adjustable aperture for controlling the cross-sectional area of an X-ray beam.

It is frequently desirable to vary the crosssectional area of an X-ray beam when making fluoroscopic or radiographic exposures. This has been accomplished generally by means of a beam limiting cone assembly havin an adjustable diaphragm opening for the passage of the X-rays. The prior arrangements, however, have not been satisfactory because it was necessary that the shutters be positioned sufficiently distant from the focal spot to aiford maximum control of the beam aperture. This materially increased the size of the X-ray equipment because of the neoessity of maintaining adequate cross travel. Furthermore, the prior shutter arrangements exhibited halo and stray radiation effects which were undesirable when making exposures.

Accordingly, it is an object of the invention to provide an improved compact X-ray cone assembly wherein the cross-sectional area of the beam may be varied in two dimensions.

It is a further object of the invention to provide an X-ray cone assembly having shutter members which are located as far from the focal spot as possible consistent with maintaining the necessary cross travel and without unduly increasing the width of the X-ray unit.

Another object of the invention is to provide an Xray cone assembly adapted to yield a sharp image cut-off on the screen or film without the presence of halo or stray radiation effects.

Further objects of the invention will appear from the following description.

Accordin to the invention these objects are achieved by providing an X-ray cone assembly having a housing open at one end thereof to define a diaphragm opening and two pairs of crossed separably actuable shutters pivoted on the housing for determining the cross-sectional area of the diaphragm opening.

In a preferred embodiment of the invention one pair of the shutters is rotatably mounted on the exterior of the housing and the other pair thereof is rotatably mounted internally in the housing. Means are further provided for selectively rotating the shutters to vary the crosssectional area of the diaphragm opening. The shutters of the pair mounted externally on the housing are given a generally L-shaped configuration while the shutters of the pair mounted internally in the housing are generally planar in shape.

8 Claims. (Cl. 250-405) The invention will be described in greater detail with reference to the appended drawing in which:

Fig. 1 is a perspective View of an X-ray shutter apparatus according to the invention, and

Fig. 2 is an interior plan View of Fig. 1.

Referring to Fig. 1 of the drawing an X-ray protective cone l is shown provided with an outer set of shutters 2 and 3 and an inner set 4 and 5 for adjusting the diaphragm aperture 6 limiting the beam of X-radiation generated by a tube 1 in a housing 8 secured by means of a flange 9 to the cone. The outer shutter members are mounted on the top and bottom respectively of the housing and are hinged for rotary movement opening and closing the diaphragm aperture vertically. The outer shutters are generally L-shaped and swing in arcs from a completely open position to a closed position where the shutters contact one another and close the diaphragm completely.

The inner shutter members are plates arranged to pivot about two shafts l0 and II internally in the housing and likewise regulate the width of the diaphragm from a completely open position when the shutters lie fiat against the walls of the housing until the shutters close and thereby close the diaphragm aperture completely. The four shutters are adjustable to control the width of the diaphragm aperture both horizontally and vertically and thereby giving an aperture of selectively variable cross section.

The walls of the cone I and the shutters 2, 3, 4 and 5 are constructed of a material, such as lead, which is substantially impervious to X- radiation.

The outer shutter members are hinged at the top and bottom of the casing respectively through a shaft member l2 journalled in two bearings only one of which, [3, is shown in the drawing, the other bearing being hidden in the view shown. Similarly, the bottom shutter is likewise hinged for movement simultaneously with the upper shutter. The mechanism for moving the outer shutter 2 comprises a shaft 14 rotatable by a crank (not shown) causing a linkage unit comprising a first lever 15, an arm l6, and a second lever I! to rotate shaft l8. Connected to the shaft are two hinges I9 and 20 which are coupled to two arms 2| and 22. A pin 23 is journalled in the arms 2| and 22 and in a mounting bracket 24, so that rotation of the shaft results in rotary movement of the shutter.

In a similar manner the bottom shutter 3 is 3 operated by a linkage assembly comprising an arm and a lever 26 which rotates shaft 27 causing the shutter to move in a manner similar to the upper shutter described above.

The inner shutters are rotated by a notched tubular shaft 28 which rotates a linkage assembly comprising a lever 29, an arm 30, and a second lever 3|. Movement of the latter lever imparts rotary motion to shaft 32 causing worm gears 33 and 34 to rotate pinion gears 35 and 36 which cause shafts lo and H to rotate carrying the inner shutters 4 and 5.

The mounting of the inner shutters for rotary movement is shown more clearly in Fig. 2 wherein the shutters are mounted on the respective shafts 9 and It by means of collars 31 and 38 press-fitted thereon and secured by means of pins 39 and 40 to the shutters. Movement of the shafts causes the shutters to rotate inwardly or outwardly depending on the particular adjustment desired.

The driving assembly is secured to the housing by means of a mounting bracket 41.

While I have described my invention in a specific use thereof and in a specific embodiment, I do not Wish to be limited thereto for obvious modifications Will occur to those skilled in the art without departing from the spirit and scope of the invention.

What is claimed is:

1. An X-ray cone assembly, comprising a housing member open at one end thereof defining a diaphragm opening for the passage of an X-ray beam of predetermined cross-sectional area therethrough, a diaphragm constituted by two pairs of shutters separably actuable for determining the cross-sectional area of the diaphragm opening, one pair of said shutters being rotatably mounted on the exterior of said housing to adjust one dimension of the said cross-sectional area of said diaphragm opening, the other pair of said shutters being rotatably mounted internally in said housing to adjust the other dimension of the said cross-sectional area of said diaphragm opening,

said second pair of shutters being arranged to constitute an X-ray beam limiting cone Whose largest diameter corresponds to the diaphragm opening formed by said second pair of shutters, and means operable to selectively rotate said shutters to vary the cross-sectional area of said i diaphragm opening.

2. An X-ray cone assembly, comprising a housing member open at one end thereof defining a diaphragm opening for the passage of an X-ray beam of predetermined cross-sectional area therethrough, a diaphragm constituted by two pairs of shutters separably actuable for determining the cross-sectional area of the diaphragm opening, means pivotally to mount one pair of said shutters on the exterior of said housing to adjust one dimension of the said cross-sectional area of said diaphragm opening, means pivotally to mount the other pair of said shutters internally in said housing to adjust the other dimension of the said cross-sectional area of said diaphragm opening, said second pair of shutters being arranged to constitute an X-ray beam limiting cone whose largest diameter corresponds to the diaphragm opening formed by said second pair of shutters, and means operable selectively to rotate said shutters to vary the cross-sectional area of said diaphragm opening.

3. An X-ray cone assembly, comprising a housing member open at one end thereof defining a diaphragm opening for the passage of an X-ray beam of predetermined cross-sectional area therethrough, a diaphragm constituted by two pairs of shutters separably actuable for determining the cross-sectional area of the diaphragm opening, means pivotally to mount each shutter in one pair thereof along parallel axes on the exterior of said housing to enable adjustment of one dimension of said cross-sectional area of said diaphragm opening, means pivotally to mount each shutter in the other pair thereof internally in said housing along axes perpendicular to said parallel axes to enable adjustment of the other dimension of the said cross-sectional area of said diaphragm opening, said internally mounted pair of shutters being arranged to constitute an X-ray beam limiting cone whose largest diameter corresponds to the diaphragm opening formed by said second pair of shutters, and means operable selectively to rotate said shutters to vary the cross-sectional area of said diaphragm opening.

4. An X-ray cone assembly, comprising a housing member open at one end thereof defining a diaphragm opening for the passage of an X-ray beam of predetermined cross-sectional area therethrough, a diaphragm constituted by two pairs of shutters separably actuable for determining the cross-sectional area of the diaphragm opening, means pivotally to mount each shutter in one pair thereof along first parallel axes on the exterior of said housing, means pivotally to mount each shutter in the other pair thereof internally in said housing along second axes perpendicular to said first axes, said internally mounted pair of shutters being arranged to constitute an X-ray beam limiting cone Whose largest diameter corresponds to the diaphragm opening formed by said second pair of shutters, first linkage means coupled to said one pair of shutters to rotate said one pair of shutters about said first axes thereby to adjust one dimension of said cross-sectional area of said diaphragm opening, and second linkage means coupled to said other pair of shutters to rotate said other pair of shutters about said second axes thereby to adjust the other dimension of the said cross-sectional area of said diaphragm opening.

5. An X-ray cone assembly, comprising a housing member open at one end thereof defining a diaphragm opening for the passage of an X-ray beam of predetermined cross-sectional area therethrough, a diaphragm constituted by two pairs of shutters separably actuable for determining the cross-seotional area of the diaphragm opening, hinge means pivotally to mount each shutter in one pair thereof along first parallel axes on the exterior of said housing, shaft means pivotally to mount each shutter in the other pair thereof internally in said housing along second axes perpendicular to said first axes, said internally mounted pair of shutters being arranged to constitute an X-ray beam limiting cone whose largest diameter corresponds t the diaphragm opening formed by said internally mounted pair of shutters, first linkage means coupled to said one pair of shutters to rotate the shutters of said one pair of shutters in opposite directions about said first axes thereby to adjust one dimension of said cross-sectional area of said diaphragm opening, and second linkage means coupled to said shaft means to rotate the shutters of said other pair of shutters in opposite direction about said second axes therebyto adjust the other dimension of said cross-sectional area of said diaphragm opening.

6. An X-ray cone assembly, comprising a housing member open at one end thereof defining a diaphragm opening for the passage of an X-ray beam of predetermined cross-sectional area therethrough, a diaphragm constituted by two pairs of shutters separably actuable for determining the cross-sectional area of the diaphragm opening, hinge means pivotally to mount each shutter in one pair thereof along first parallel axes on the exterior of said housing, shaft means pivotally to mount each shutter in the other pair thereof internally in said housing along second axes perpendicular to said first axes, said inter--- nally mounted pair of shutters being arranged to constitute an X-ray beam limiting cone Whose largest diameter corresponds to the diaphragm opening formed by said internally mounted pair of shutters, first linkage means coupled to said one pair of shutters to rotate the shutters of said one pair of shutters in opposite directions about said first axes, second linkage means coupled to said shaft means to rotate the shutters of said other pair of shutters in opposite directions about said second axes, and means separably operable to actuate said first and second linkage means thereby to vary the cross-sectional area of said diaphragm opening.

'7. X-ray apparatus, comprising an X-ray tube housing, a window in said tube housing, and an X-ray cone assembly coupled to said tube housing and comprising a cone housing member open at one end thereof defining a diaphragm opening for the passage of an X-ray beam of predetermined cross-sectional area therethrough, a window in the other end of said cone housing arranged adjacent to the window in said tube housing, a diaphragm constituted by two pairs of shutters separably actuable for determining the crosssectional area of the diaphragm opening, one pair of said shutters being rotatably mounted on the exterior of said housing to adjust one dimension of said cross-sectional area of said diaphragm opening, the other pair of said shutters being rotatably mounted internally in said housing to adjust the other dimension of said crosssectional area of said diaphragm opening, said internally mounted pair of shutters being arranged to constitute an X-ray beam limiting cone Whose largest diameter corresponds to the diaphragm opening formed by said internally mounted pair of shutters, and means operable selectively to rotate said shutters to vary the crosssectional area of said diaphragm opening.

8. X-ray apparatus, comprising an X-ray tube housing, a window in said tube housing, and an X-ray cone assembly coupled to said tube housing and comprising a cone housing member open at one end thereof defining a diaphragm opening for the passage of an X-ray beam of predetermined cross-sectional area therethrough, a window in the other end of said cone housing arranged adjacent to the window in said tube housing, a diaphragm constituted by two pairs of shutters separably actuable for determining the cross-sectional area of the diaphragm opening, means pivotally to mount each shutter in one pair thereof along parallel axes on the exterior of said housing to enable adjustment of one dimension of said cross-sectional area of said diaphragm opening, means pivotally to mount the shutters in the other pair thereof internally in said housing along axes perpendicular to said given axes to enable adjustment of the other dimension of said cross-sectional area of said diaphragm opening, said internally mounted pair of shutters being arranged to constitute an X-ray beam limiting cone whose largest diameter corresponds to the diaphragm opening formed by said internally mounted pair of shutters, and means operable selectively to rotate said shutters to vary the cross-sectional area of said diaphragm opening.

MAX KNAB.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,250,730 Waite Dec. 18, 1917 1,813,383 Chesney et al July '7, 1931 2,204,465 Baier June 11, 1940 2,331,586 Waisco Oct. 12, 1943 FOREIGN PATENTS Number Country Date 461,387 France Jan. 27, 1914 532,528 France Nov. 16, 1921 Add. 25,897 France Feb. 27, 1923 

